[HELP] dafault math.h

### Description

How to replace the default math.h. I tried to use libmcs as my default math lib. I have to directly include "libmcs/math.h" to use libmcs math lib. But I want to directly include math.h in libmcs. I tried the method mentioned in #1503. However when I include math.h it still links to the math lib supplied by my toolchain. Any idea to achieve that?

### Verification

- [X] I have verified before submitting the report.

Start by reviewing the approach mentioned in #1503 and tracing how math.h versus libmcs/math.h is resolved by the NuttX toolchain and linker. Done means establishing a supported way to include math.h while selecting libmcs instead of the toolchain's math library, or clearly documenting why that is not possible.

Written by the indexing model from the issue text.